Known in the art is a differential scanning microcalorimeter, the adiabatic shell of which accommodates two capillary calorimetric chambers, the ends extending from the adiabatic shell passing through a heat bypass serving for limiting the working volumes of the chambers, with external surfaces of the adiabatic shell, capillary calorimetric chambers and heat bypass mounting thermal sensing elements and heating elements electrically coupled with temperature controls (cf. U.S. Pat. No. 3,899,918, cl. 73-15B, 1975).
The capillary calorimetric chambers of the microcalorimeter constitute separate volumes with the result that mixing of liquid media is impossible, and, hence, the heat of mixture of these media cannot be measured.
There is also known a reactive microcalorimeter (cf. Gill S.T., Chen V., RS I 43 (1972) 774-776; Wadso I, Quarterly Review of Biophysics 3, 4 (1970) 383-427) designed for measuring the heat of mixture of two liquid media at a constant temperature. The microcalorimeter comprises two capillary tubes to supply liquid media, a mixer, a tube to release liquid mixture, a temperature sensor to measure the temperature difference between the supply and release tubes, and a thermostat.
However, this microcalorimeter operates at a constant temperature and does not permit estimates of the effects involved in warming-up, i.e., measurements of the differential calorific capacity.
Therefore, complete physicochemical examination of liquid media, including measurements of the differential calorific capacity of composite media and measurements of the heat of mixture of two media at different temperatures, can be conducted by means of two different instruments: by a scanning microcalorimeter and by a reactive microcalorimeter, whereby measurements taken by two microcalorimeters take much time since the objects of study must be repeatedly transferred from one instrument to the other, and the microcalorimeter operating conditions must be readjusted. Considering that the change of the fixed temperature in a reactive microcalorimeter commonly takes several full days, the fact that the foregoing physicochemical examinations have not been actually practiced till now is quite explicable.